
width = 150px
height = 46px
arrowSize = 5px
aWidth = width*0.8

  // 主菜单
  ul
    margin 0
    padding 0
    list-style none
    &:first-child
      transition-duration .5s
      opacity 0.2
      &:hover 
        opacity 1
    //TODO: 非hover时隐藏左侧导航栏
    // position relative
    // left -109px
    // i 
    //   position absolute
    //   left 120px
    // &:hover 
    //   left 0px
    //   i 
    //     position relative
    //     left 0

    li
      &:first-child 
        border-top-right-radius 3px
        a
          padding-top 13px
      &:last-child
        border-bottom-right-radius 3px
        a
          padding-bottom 13px
  
      
  
  li
    // position relative
    background #efefef
    &:hover
      background #fff
      >ul
        display block
    ul // 子菜单
      width width
      padding-left 10px
      display none
      position absolute
      margin -1*height 0 0 width
      // top 0
      // left 100%
      li 
        &:first-child
          border-top-left-radius 3px
          border-right-color #efefef
          &:before // 小箭头
            color #efefef
            position absolute
            content ""
            width 0
            height 0
            margin 0.5*height 0 0 -1*arrowSize
            border-top arrowSize solid transparent
            border-bottom arrowSize solid transparent 
            border-right:arrowSize solid @color
            border-right-color inherit
        &:last-child
          border-bottom-left-radius 3px
        
        &:hover
          border-right-color #fff
  a
    display inline-block
    width aWidth
    padding 8px 15px
    cursor pointer
    color #483430
    text-decoration none
    //TODO: 设置图标变色过渡时间 transition-delay 0.5s
    &:hover, &.router-link-active
      i
        color deepskyblue
.menu-item 
  padding-left 5px
  padding-right 5px